Alternating-electric-current control system



Feb. 28, 1928.

E. B. THURSTON ALTERNATING ELECTRIC CURRENT CONTROL SYSTEM Filed Sept.28, 1923 safet Y ill Ill)

Patented Feb. 28, 1928.

UNITEn STATES PATENT OFFICE.

ERNEST B. THURSTON, OF TOLEDO, OHIO, ASSIGNOR TO THE HAUGHTON ELEVATOR &MACHINE C0,, 01? TOLEDO, OHIO, A CORE'ORATION OF OHIO.

ALTERNATING-ELECTRIC-CURRENT CONTROL SYSTEM.

Application filed September 28, 1923.

This invention relates to safety features in electrically controlledinstallations.

This invention has utility in. connection with torque motor control forpolyphase electrical circuits in the operation of elevators. In itspresent embodiment the invention comprises an installation including areversible polyphase alternating current motor, a power supply therefor,ma1n and direction switches, electric actuating means for the mainswitches, additional electric actuating means for the directionswitches, a controller for the actuating means, resistance between thecontroller and the supply, a speed controlled governor for holding thedirection switch in, when mot-or is oper ating above a predeterminedspeed, a connection to the controller through said direction switch andspeed controlled device by-passnup said resistance and (to-acting, uponshifting the controller motor versal, to connect the main switchactuating means for a power connection which insures opening the mainswitch.

One object of the invention is to provide mlvphase actuating devices forthe switches of? an elevator system, which enable the switches, undercertain conditions, to be positively operated in either direction. An-

other object is to prevent reversal oi? the elevator motor when itsspeed exceeds a predetermined value.

Referring to the drawings vFig. 1 is a wiring diagram oi? an embodimeutol? the invention in a three phase reversible two speed induction motorelevator installation, parts being broken away, and

Fig. 2 is a wiring d'hgram illustrative of the principle for efi'ectingpower throwing out (it the high speed main switch on motor reversal.

In elevator shaft 1 having landings 2 is shown elevctor ear 3 havinghoisting cable 4; extending around drum 5 on shaft 6 above the elevatorwell 1. This cable l utter passing around the drum 5e31tends about idler7 to counterweight 8. Induction motor 9 on shaft 10 has ball governor11, brake drum 12, and won 13 thereon. This worm 13 is in l'uesh withworm wheel ll for operating the shaft (3 and through the drum 5 andcable eliecting raising and lowering of the elevator ear 8 in the wellor shaft 1 between dill'erenli landings 2. 1n the elevator car 8 1Scontroller 15 having contacts 16, 17.

Serial No. 665,297.

Power supply line 18 has branch 19 through resistance 20 thence by line21 through terminals at upper stop limit switch 22 to line 23 extendingto terminal 24 at the contact 16 or the controller 15. Assuming thecontroller 15 is shifted to the right for effecting up direction travelof the elevator car 3 in the well 1, this contact 16 is shifted to connect the terminal 24 with terminal 25 having connection by way of line26 through tern'iinals at door switches 27, closed when the landingdoors to the elevator well 1 are closed, thence by line 28 through thecoil at relay 29, and by line 30 to power supply line 31. As the initialmovement of the controller 15 thus energizes the relay 29, the line 87,which is adapted to be connected to power supply line 18, when thedirection switch 38 is closed, is connected through branch 36, brakecoil 35, line 34, relay 29 and line 33 to power supply line 31; branch36 is also connected through brake coil 39, line 40, relay 29 and line41 to line 42 which, when the direction switch is closed, is connectedto power supply line 43.

T 1e power supply line 43 has a branch line ll which, when the relay 29is closed, is connected through linel5 and through resistance 46 to line47 extending to terminal 4-8, at the contact 17 of the controller 15. Atthe first position of the controller 15 connecting terminals 24; and 25,this terminal 48 is not necessarily connected through contact 17However, upon further shifting of the controller, the contact 17 isbrought to the terminal 49 and thereby the terminal l8 through thiscontact 17 is connected with line 50 extending to winding 51 of torquemotor 52. As the contact 17 engages the terminal 4-9 the contact 16engages terminal 58 connecting the line 23 with line 54: we tending towinding 55 at the torque motor 52. Third winding 56 at this torque motor52 has line 57 therefrom through various safety devices, as emergencyswitch, over travel switches, slack cable switches, safety speedgovernor, etc., thence by line 58 to the power supplyline 31. Thistorque motor or polyphase switch actuating device 52 is accordinglyenergized to rock shaft '59, and through up direction cam 60, to closethe switch 88 and thereby connect the power supply 18 with the line 37and the power supply line 1 3 with the line 42, ell'ective through thecontacts at the relay 29 for energising the brake coils 35, 39, andthereby swinging brake shoes 61 clear of the drum 12 against theresistance oil spring 62.

The low speed switch 63 is held normally closed by a cam 80 on a rockshaft 7 9. This roclr shalt is adapted to be rocked by a torque motor 71 to a position for releasing the switch 63 and permitting it to open,at the same time closing the high speed main switch 32 by means 01 thecam 81. lin the normal operation of the system, as soon as the torquemotor '24 is de-energized, the rock shaft 79 returns to its normalposition in which the low speed switch 63 is closed. 1t is to beunderstood that when the shaft 79 is at the limit 01 its movement in onedirection the cam 80 is effective and when it is at the other limit ofits position the cam 31 is etl'ective.

Normally closed low speed switch 63 conneots the power line 31 throughline 641 to low speed winding 65 at the motor 9. The

closing of the up direction switch 38 connects the power supply line 18with the line 3"? extending to low speed winding 06. This up directionswitch is also effective in connectin the power supply line 13 with theline 12, which, at the low speed switch 63 is connected to line 67extending to low speed winding 63. Accordingly at this position of thecontroller 15, the motor 9 is energised for low speed operation and thebralre shoes 61 are released from the shalt so that the elevator 3 maybe operated upward at low speed. Further shifting of the controller tothe right, brings the contact 16 to terminal 69 connected by line Z 0through terminals at upper slow down limit switch "6' 1, thence by line72 to winding 13 at torque motor 7 1. As this contact 10 is moved to theterminal 69, the controller contact 1'? is brought to terminal T 1connecting the line 4'? to line 75 extending to winding 16 at the torquemotor 'Z l. 'llhird winding W at the torque motor 'M is connected byline 73 to the line 3 1 extending through terminals at the relay 29 tothe line 33 connected to the power line 31. Accord ingly this mainswitch polyphase alternating current actuating device or torque motor W1is ettective for rocking its shaft 7 9 to shitt slow speed switch cam 80to permit the slow speed switch 63 to open, while high speed cam 31 onthe shaft 79 throws high speed switch 32 into closed position. Thisclosing of the high speed switch 32 connects the power supply 31 to line83 extending to high speed winding 84: at the reversible two speed.motor 9. The power line 12 from the up direction switch 33 extends tothis switch 32, is there connected to line extending 10 high speedwinding 86 at the motor 9.. 'llhird high speed winding 87 for this motor9 is connected by line 38 to the line 3'1 i llhis reversible two speedinduction ind neenoae tor 9 is accordingly now connected up for highspeed driving of the elevator 3 upward.

As this motor 9 gets the shaft 10 up to speed, fly ball governor 11 as aspeed control device causes contact 89 to connect branch 93 from theline 36 with line 91. extending to the line This fly ball governor 11also carries contact 92 ellective to connect branch 90 oi the line 4-1with a line 91 leading to the line 50. This means that with thc'shai t10 up to speed, or beyond a determined speed, this control governor 11will bypass the controller and hold the direction switch in, even thoughthe relay 29 be open. This not an interlock at the direction switch norat a main switch. This mlding in is ellective with the controller 15shi'lited baclr to central or oil position. However, even in the eventof rocking the controller 15 to a reverse position, the governor 11 willstill control the direction switch, for the contact 19 is engaged withcontact 95 from line 90 through terminals at down stoplimit switch 9?,thence by line 93 connected to the line its this contact 10 is shiftedby throwing the controller 1.5 to the left for down direction travel,the contact 10 engages terminal connected by line 100 with the line 20.This tends to hold the relay 29 closed. l urthcr shifting of thecontroller 15 to the left brings this contact 10 to terminal 101connected by line 102 with the line the same time the contact 17engaging terminal 103 from the line H is shifted over to terminal 104connected by line 105 to the line 5 4-. This does not effect reversal ofthe direction switch torque motor 52, tor the reason that the governor11 is bypassing the resistances 20, 16, and the resistances 20, 16, arein parallel with this direction switch torque motor The further throwingof this controller 15 for down direction travel, while the car 3 isstill travelling upward, brings the contact 16 to terminal 106 connectedby lin 107 through terminals at slow down limit switch 103, thence byline 109 to the line 72. Simultaneously the contact 1'? is shifted toterminal 110 connected by line 111 to the line 75. These connections tothe windings 73, 76 oil the torque motor i l bypass the resistancos 20,In this connection, the supply line 18 is connected by way of the switch38, lines 3'2, 30, itch 89, lines 91, 5 1, 105, terminal 10 1, contact1'7, lines 111, 75, to the winding 70, which winding 76, had beentllGlGlO'fOIQ supplied through the contact 7 from terminal 4:8, line 47,resistance 16, line 4:5, switch 29, line li, from the supply line 13.The supply line 13 is now connected by way of the switch 38, lines 11,90, 93, switch 92, lines 50, 102, terminal 101, contact 16, terminal106, line 107, switch 108, lines 109, 72, to the winding 73, whichwinding 73 had been tncretolore supplied tl'lrough the contact 16 fromterminal 95, line 96, switch 97 lines 98, 21, resistance: 20, line 19from the supply line 18. These connections accordingly reverse thephases at this torque motor 7 and in the event the normal gravity throwout fails, they elfect a rocking of the shaft 7 9 positively out of highspeed position for opening the high speed switch 82 and simultaneouslyclose the low speed switch 63. This reversal of the motor 74, whilestill connected up for the original high speed throw thereof, is broughtabout due to the resistances 20, 46, being in parallel with this motor74, and the direct connections being predominate. There is accordinglyherein a simple safety device insuring that any throwing of thecontroller 15 into reverse position during operation of the motor 9 athigh speed only effects cutting out of the high, speed operation of themotor. Thereafter, as the motor 9 is slowed down below a predeterminedspeed, the circuits through the contacts 89 and 92 are automaticallyopened by the governor 11, and circuits through the controller 15 andthe resistances 20 and 46 become effective in energizing the directionswitch motor 52 in the opposite direction, whereby the direction switchis actuated to close the circuit in a reverse direc tion through the lowspeed winding of the motor 9, and the motor 74 is subsequently actuatedto switch the power circuit to the high speed winding of the motor 9.

To simplify the disclosure herein there has been omitted theacceleration resistances and their control. These may be connected to beoperated by a torque motor from the lines extending to the low speedwinding for the low speed acceleration torque motor, and from the linesto the high speed windings f or the high sped torque motor. Theresistances for these accelerations may be brought out from the junctionof these speed windings for the motor.

That is claimed and it is desired to secure by Letters Patent is 1. Areversible motor, a power supply therefor, switches in said supply,electric actuating means for the switches, a controller for theactuating means, resistance between the controller and the supply, andpower supply connections by-passing the controller and rcsi, nce andadapted under certain conditions to be temporarily connected to saidactuating means reversely to the connections tln'ough said resistance,whereby the last mentioned connections are rendered ,tem orarilyineffective.

2. A reversible motor, a power supply therefor, main and directionswitches in said supply, electric actuating means for the main switches,additional electric actuating means for the direction switches, acontroller provided with connections therefrom co-acting for reversingthe motor operation, resistance between the controller and the supply,and power line connections by-passing said re. sistance and operable,when closed, to maintain the direction switch in original position afterthe connections through resistance to the direction actuating means havebeen reversed.

8. A reversible motor, a power supply therefor, main and directionswitches in said supply, electric actuating means for the main switches,additional electric actuating means for the direction switches, acontroller for reversing the motor operation, a. resistance between thecontroller and the supply, and connections through the closed directionswitch by-passing said resistance and operable, when said connectionsare closed, to maintain the direction switch in original position, eventhough the connections through resistance to the direction switchactuating means have been reversed.

4. A reversible motor, power supply lines leading thereto, switches insaid lines, polyphase electric actuating means for said switches, acontrol for said actuating means, resistance in the lines between saidsupply and said controller, and means bypassing the controller andresistance and operable in the event that the controller is moved to areverse position when the motor is operating above a predeterminedspeed, to temporarily prevent the setting of said switches in positionfor reverse operation of the motor until said motor slows down.

5. A reversible two-speed motor, power supply lines leading thereto,switches in said lines, polyphase electric actuating means for saidswitches, a controller for said actuating means, resistance in the linesbetween said supply and said controller, and means by passing thecontroller and resistance and ope able, in the event that the controlleris moved to a reverse position when the motor is operating above apredetermined speed, to maintain the switches in position for low peedoperation of the motor in the same direction, and operable after themotor has slowed down, to allow the setting of the switches for reverseoperation without any further movement of the controller. 6. Areversible polyphase motor, a power supply therefor, switches in saidsupply, electric actuating means for the switches, a controller for theactuating means, resi-iitance between the controller and the supply, andpower line connections by-passing said resistance and operable, whenclosed, under certain conditions to maintain the direction switchtemporarily in its original position even though the connections throughthe resistance to the direction switch actuating means have beenreversed.

7. A reversible motor, a power supply therefor, main and directionswitches in said supply, electric actuating means for the main switches,additional electric actuating means for the direction switches, acontroller for reversing the motor operation, a speed controlled devicefor holding a direction switch i when toe motor is operating at adetermined speed, connections to the controller through said directionswitch and speed controlled device placing said controller in circuitwith said device for ellecting through reversal oi? the controller aPOWOI connection insuring an opening of a main switch.

8. A reversible motor, a power supply theretor, main and directionswitches in said supply, electric actuating means for the main switches,additional electric actuating means for tl c direction si v ches, acontroller for ltlVGlSlllg the motor operation, resistance between thecontroller and the supply, a speed controlled device for holding adirection switch in when the motor is operating at a determined speed,a. connection to the controller through said direction switch and soeedcontrolled device bypassing said resistance and cos upon shitting thecon.- troll or for motor re ersal to connect the main switch actuatingmeans for a power connection insuring opening a main switch.

9. it reversible motor, a polyphase alternating electric current supplytherefor, main and direction switches for the motor, a polyphaseactuating device for the main switches, an additional polyphaseactuating device for the direction switches, a controller, a speedcontrolled device bypassing the conholler :lior holding the directionswitch in at a dotern'iined speed of the motor, and connectioi'is fromthe controller as thrown for reversing the directioi'i of the motor toconnect die power supply through the speed controlled device foroperating the main switch actuating device for a power connection insnriopening a main switch.

it). A mi. speed reversiblemotor, a polyphase alternating current supplythere'lior, "Htlll and direction switches for the motor, a torque motorfor operating the main swil' hos and having a plurality of current pha.thereto, an additional torque motor I opera the direction switches, acon iroller, a speed controlled device provided u ith connections in aplmrality of phases of i@ t rection switch torque motor for bypassingthe controller ilor holding the diroction switch in at a determinedspeed ol? the motor, and connections from the controller when thrown forreversing the direction ot' the motor travel for connecting the mainswitch torque motor in circuit with the controller for positivelyoperating said motor for insuring o icning a main switch.

ll. 1'3. nnilti-speed reversiliile motor, a polyphase alternatingcurrent supply therefor, main and direction switches :tor the motor, atorque lflOlZOl. for operating the main switches and having a pluralityof current phases memes thereto, an additional torque motor foroperating the direction switches, a controller, resistances in aplurality of phases between said supply and controller, a speed controlled device provided with connections in a plurality of phases of thedirection switch torque motor for bypassing the controller for holdingthe direction switch in at a determined speed of the motor, andconnections -from the controller, when thrown for reversing thedirectionot the motor travel, for connecting the main switch torquemotor in circuit with the controller for positively operating said motor:for insuring opening a main switch.

12-. i'in electric control installation embodying low and high speedmain switches, said low speed switch being normally closed, a polyphasotorque motor for actuating said switches, and a controller provided withconnections in circuit with the torque motor operable normally forsingle direction 0poration of said motor for all positions of thecontroller and operable under predetermined operating conditions toreverse said motor.

13. An electric control installation embodyin main switches, acontroller, a torque motor normally operable in one direction only, foractuating one oi said switches, said controller being provided withconnections For placing said torque motor in circuit with saidcontroller, under predetermined operating conditions, in such a way asto ellect reversal ot said torque motor for opening said last mentionedswitch.

14-. A control installation embodying main high and low speed switches,a first torque motor therefor, direction switches, a second torque motortherefor, a reversible motor to be operated from said switches, acontroller,

power supply means, connections from the controller and power supplymeans normally eli'ectivo in one direction of shifting the controllerfor operating said first torque motor in one direction and said secondtorque motor inone direction, connections normally ell'ective in theother direction of shifting of the controller for tending to operate thefirst torque motor in said one direction only and for oppositelyoperating the second torque motor, and additional connections effectiveupon reversal of the controller with the reversible motor still rotatingabove a predetermined seed precluding reversal of the second torquemotor and etl'ecting reversal of the first torque motor.

15. In an electric elevator installationhaving low speed and high speedcircuits, switches controlling the. energization ol'said circuits, amotor operrt ng said switches and a car-switch controlling said switchmotor, connections whereby movement of the ar-switch from high speedposition for one direction of the elevator travel to high speed positionfor the other direction of the elevator travel, when the elevator istraveling in the first said direction at a speed as great as apredetermined minimum, reverses the current to said switch motor andcauses the same to positively switch the current from the high speedcircuit to the low speed cireuit.

16. In an electric elevator installation having low speed and high speedcircuits, switches controlling the energization of said circuits, amotor operating said switches and a car-switch controlling said switchmotor, connections whereby movement of the car switch from high speedposition for one direction of the elevator travel to high speed positionfor the other direction of the eleator travel, when the elevator istraveling in the first said direction at a speed as great as apredetermined minimum, reverses the current to said switch motor andcauses the same to positively switch the current from the high speedcircuit to the low speed circuit, and speed-controlled means preventingthe energization of said switch motor in the direction to energize thehigh speed circuit in the reverse direction until a predetermined lowspeed has been attained.

In witness whereof I afiix my signature.

ERNEST B. THURSTON.

